An air conditioner performs heat-exchanging by introducing outside air and discharging the heat-exchanged air to the outside. A filter is usually disposed in the air conditioner so as to filter foreign substances from the introduced outside air. Also, a filter is provided in a dehumidifier, a humidifier, and so on, in addition to the air conditioner.
When the air conditioner having the filter is continuously driven, outside air passes through the filter continuously, and foreign substances are stacked in the filter and may disturb introduction of the air. In order to prevent this problem, a cleaning device for cleaning the foreign substances attached to the filter can be used.
In some cases, a brush of the cleaning device may continuously separate dust attached to the filter. However, when the brush operates continuously, the dust can become attached to the brush such that efficiency of filter cleaning is lowered.